NEW YORK >> Since “Bend It Like Beckham” instantly made her a teenage superstar 22 years ago, Keira Knightley has done virtually everything an actor can do. She has appeared in World War II dramas and apocalyptic comedies. She has sung and played the guitar. She has even — gasp — performed in an American accent.

But unlike other A-list Oscar nominees, Knightley has yet to star in a glossy streaming series — until now. In “Black Doves,” a witty, blood-splattered spy thriller and surprisingly thoughtful exploration of friendship set in London at Christmas, she stars as a woman leading an increasingly complicated double life.

Written and created by Joe Barton (“Giri/Haji”), the Netflix series follows Helen Webb, the posh wife of a conservative politician and devoted mother of twins who has also spent many years as a professional assassin working for a covert organization called the Black Doves. When Helen’s secret lover Jason (Andrew Koji) is killed, her elusive boss, Reed (Sarah Lancashire) senses that Helen is in danger and persuades Sam (Ben Whishaw), a former Black Dove and Helen’s closest confidant, to come out of retirement to protect her. The old friends reunite to investigate Jason’s death, slowly unraveling a plot with global consequences and unleashing carnage across the city.

Knightley, whose last live-action TV role was in a BBC adaptation of “Doctor Zhivago” in 2002, has been looking to do something on the small screen for some time. After some heavier projects, like last year’s “The Boston Strangler,” she was keen to find something fun and fizzy.

“My teenage self is thrilled with this. Sometimes you have to listen to your teenage self and go, ‘This one’s for you,’ you know. I think she would have found this very cool,” says Knightley in a video call from London, where she lives with her husband, musician James Righton, and their two daughters.

Knightley also wanted a role that was gnarled and complicated enough to sustain her interest through a six-month shoot and potentially multiple seasons.

“Helen was just so weird and incorporated so many strange, oppositional things at the same time,” says Knightley, who also liked the idea of working close to home. “Not having to take my kids out of school was bliss.”

Barton, who met with Knightley early in the writing process, felt the actor was uniquely capable of capturing Helen’s numerous contradictions.

“People know the period drama, Jane Austen side. But she’s done ‘Pirates of the Caribbean’ and ‘Domino,’ she’s done silly and also very serious. She’s a really fantastic, underrated actor,” he says, citing her ability, in films like “Atonement,” to play “characters that are desperate to break out from the societal restraints put on them. … She does ‘below the surface, striving to escape from something’ really well.”

Plus, she adapted seamlessly to the frantic pace of making television, Barton says: “Once you’ve survived Jerry Bruckheimer, you can survive a TV schedule.”

Knightley spoke to The Times about making “Black Doves,” which is now streaming, the perils of early fame and her unvarnished feelings about “Love Actually.” The conversation has been edited and condensed for clarity.

Q Helen is this fascinating contradiction — a genteel Tory wife who is also a ruthless assassin. What was intriguing to you about her?

A I loved the idea of this person who’s made a life choice 10 years ago that she cannot take back, and she’s regretting having to live with that decision and there being no way out. I thought that was very rich. As was the relationship with her husband. You’ve had children with this person. There is love there. But what is that love, if you’re betraying them the whole time?

Q We know very little about Helen’s backstory. Was that challenging for you as a performer?

A She’s definitely an enigma. What I could create was an idea of what childhood might have been like for somebody to make the choices that she’s made. That is interesting to think about: somebody who has to feel that they have the power over people at all times, and that by betraying them, they have control. Where do you come from if you need that kind of control? If you need to betray them before they betray you?

Q The Helen-Sam relationship really becomes the focal point of the series. What is the nature of their bond?

A They’re allowed to be their whole selves. With everybody else, their self gets compartmentalized, which I think we do in life. You are a parent, therefore your mum self is the one that your children see. But you have this old friend where you’re allowed to be all of these other parts of yourself. I thought that was a lovely thing to have that at the center of [the show]. It is obviously a platonic relationship, and yet it’s probably the most meaningful relationship in both of their lives.

How can you have true love or a fulfilling life if the people in your life don’t know your whole self? I’m a big [John] le Carré fan, and it’s the melancholia that I love — the cost of those double lives, of never being known. “Black Doves” has that. Whilst also being silly, and people are being blown out of buildings, it has that texture of melancholia and loneliness underneath it.

Q You got to do some memorable fight scenes in this, including a gun battle where your character is hugely pregnant. Was that oddly empowering?

A People were so shocked. It was really interesting on set that day. Everybody there was like, [makes horrified face]. But having been a very angry pregnant woman — twice — I was like, “No, this makes sense.” I like the idea that she’s pregnant with twins and is so uncomfortable. She had these very sad Tory wife loafers on. I loved the juxtaposition of that with shooting the gun.

Q A few years ago, you wrote a powerful essay about the double standards faced by mothers in the industry. Is that something that you continue to face?

A The double standards are still there throughout society. I think the industry has [improved] a lot in the last 10 years. There are many more women behind the scenes now, in the camera and electrical departments, and you never would have seen that 15 years ago. But it’s a brutal industry for working mothers. You lose so many women as soon as they [have children] because the hours are impossible and you never know what country you’re going to be in.

Q You started acting at a very young age. Would you allow your kids to act if they wanted to?

A They haven’t expressed an interest, but I wouldn’t allow them to do anything public until they were grown up. I think their privacy is very important.

I was very lucky. I did little bits [of acting] during my summer holidays, nothing was massively successful. It was only a positive experience for me. It wasn’t until I was 16, with “Bend It Like Beckham,” that it suddenly blew up.

Q That’s a lot to handle. But you also had some amazing opportunities. How do you look back on it all?

A It’s very brutal to have your privacy taken away in your teenage years, early 20s, and to be put under that scrutiny at a point when you are still growing. Having said that, I wouldn’t have the financial stability or the career that I do now without that period. I had a five-year period between the age of 17 and 21-ish, and I’m never going to have that kind of success again. It totally set me up for life. Did it come at a cost? Yes, it did. It came at a big cost. Knowing the cost, could I, in all good conscience, say to my kid, you should do that? No. But am I grateful for it? Yes. But then that’s life, isn’t it? Luckily, my kids are completely uninterested.